Reading in the owners manual the function of the "Sport" mode, to extend the range of the transmission to make full use of the engine's reserves?
I gather that this only pushes the rev limits of each shift point, or has anyone got a better explanation of this switch. Also, has anyone done a a mpg determination of the use of this switch? or is this a case of," if you have to ask, you do not need to ask?"

 

The sport switch changes the tranny shift map to shift at higher rpms. In the XKR, if it has the electronic shocks, it sets them to hard for higher speed suspension control. It goes without saying that in sport, you will use more gas, but who cares?

 

If you have the 722.6 (W5A580) gearbox (4.0 XKR) you also have a REVERSE gear ratio change.

Two reverse speeds activated by the SPORT SWITCH.

bob

 

Sam, what car are you referring to? If the '17 F type, I expect it has interactive shocks. On my '06 sport mode does not allow 6th gear, and that lowers mileage on interstates. I revert to standard when cruising over 60 mph and see 28 mpg.

 

Sam, I've always found mileage to be better with Sport turned on. I once posted a query about this same topic a while back and was surprised how many of us found the same thing.

Maybe it has to do with the length of time it is turned on. My sport switch is enabled 99% of the time. It's just the times my dog steps on it (turning it off), or there occasions that I want to feel it winding out in a higher gear at full throttle that I turn it off.

Ttytt turning it off often it falls into the "just creates stress" category. I know in the back of my mind when and where downshifts should occur. When sport is off the shift points change . God knows I've read about these trannys dying at high miles and I catch myself thinking "uh oh what's wrong- is the tranny ok?" before I recall that sport is off. Shes not supposed to shift or downshift there (whew).

John

 

Ha...i thought i was the only one to have a dog step on the sport mode switch....she is a little dog, and has activated the hazzards before also

 

the early XKR years also have the interactive shocks, don;t they ?

if 60 is your minimum speed, what is the maximum speed when getting 28 mpg ? I'm not seeing anywhere close to that on my '02 XKR even when I'm stuck with interstate travel at a steady 80 mph set on the cruise control.. Stock 4,0 s/c.

Z

 

Fellas
I'm super impressed with RJ237's 06 XK8's 28mpg! Wow! I presume that's with a 4.2L. For my 1999 XK8 4.0L na I get 16 to 17mpg in normal mode. In sports mode, this drops to 14mpg. This obviously is from the trip computer, but tallies up with the odometer & fuel I put in the car.
BTW Fuel is cheap in Bahrain so I don't mind. With a 4L engine, fuel efficiency shouldn't be what you're looking for in the car.

 

The XKR is going to use more fuel. My '06 has the six speed, and that makes the difference. Around town I use sport mode and and it drops to 16 or so, but there are a lot of traffic signals and stop signs and it's not flat.

 

I once left my car in Sport Mode for a long trip and my gas mileage was horrible. I only use it intermittently now.

 

it may be counter-intuitive, but many supercharged cars are getting better gas mileage when the rpm is kept low, as it will be w/ highway cruising while in cruise control mode. Low rpm forced induction actually improves engine efficiency. Even my Shelby''s w/ vintage Paxton ball drive superchargers would break 20 mpg @ 80+ mph with a 1:1 top gear (4 speed). whereas they they wouldn't get that mpg before the supercharger was put on.

Now when you (understandably) step on the go-go pedal, well, just don't examine the mpg too closely. Whenever I've had the sport mode on for some exercise, I generally zero out the mpg /odometer/ . That way I'm not confronted with the cost of my good times.....

Were you sensing that the transmission never shifted into high gear, as has been reported is the case ? No high gear going to be the mpg killer.

When I'm in town, I never use the sport mode, theres just no satisfaction in driving in traffic when the engine is rarin' to go, but can't. That just adds to the satisfaction when a twisty 2 lane & deserted road is on the horizon.

Z

 

Most of you verified what I suspected, that the 'Sport' switch just extends the shift points on the tranny for the XK8. On my F-Type, the "Dynamic Mode" does quite a bite more(shocks, shift pints, exhaust cutout). I would expect reduced mileage, especially around town driving.
I am still trying to find the steps to reset the Avg.accumulated Mpg. I am getting it displayed, and accumulated, but cannot get it cleared/reset. Maybe it is just me, but it seems the that the owner's manual is not the most explicit. Seems to leave a lot to the imagination.

 

the supercharger is bypassed when not in boost. Either with vacuum or with electric solenoid for the newer 5.0 and 3.0.
As for the sport switch i always leave mine on because of the biggest benefit. "passing" when you punch it to pass. It drops down 2 gears not just one giving much better acceleration

 

Does the double gear drop happen on the XK8 too or just the XKR?

 

happens on them all, go try it

 

 

That is an interesting idea. I didn't realize it got that far into the engine.

 

It should be reset by holding down the 000 button in the group of buttons that control the trip counters, up on the dash. Hold it for five to ten seconds.

You have to have one of the trip counters displayed while doing it, so the display needs to start with A: or B:. That is to say, you can't do the reset while looking at something like inst. MPG.

 

Thx. I will try that. I don't think I was holding it down. Just pushing and releasing.